The present invention relates to a cured ethylene.multidot..alpha.-olefin copolymer-based rubber composition and in particular to a cured ethylene.multidot..alpha.copolymer-based rubber composition excellent in weathering resistance property.
Cured ethylene .multidot..alpha.-olefin copolymer-based rubbers are superior in weathering resistance property and heat resistance to natural rubbers and general-purpose rubbers such as styrene-butadiene rubber, butadiene rubber, and isoprene rubber and are widely used as automobile parts, industrial parts and electrical parts by making the best use of their characteristics.
Various researches have been so far made to improve properties of the cured ethylene.multidot..alpha.-olefin copolymer-based rubbers.
For example, a cured ethylene.multidot..alpha.-olefin copolymer-based rubber composition with an improved weathering resistance property, obtained by curing an uncured rubber composition comprising an ethylene.multidot..alpha.-olefin copolymer-based rubber, a hindered amine-based weathering stabilizer, a phenol-based antioxidant and a benzotriazole-based ultraviolet absorber with an organic peroxide is proposed (JP-A-63-46246).
However, the weathering resistance property of the resulting cured rubber composition is improved only in the discoloration resistance and bending property, but improvement of tensile strength and elongation are not satisfactory. Improvements of the latter properties are now keenly desired.